Abstract:The study of the data link system networking and data transmission technology is very important to the build of the independent data link system and the test & evaluation of the data link system. At the same time, it can not only verify the validity of the designed data link system, but also is useful to understand the main functions of the data link and performance parameters, which can lay the foundation for further research and design of measurement and control data link technology. It analyzed the technology of the data link system, data link networking and the data transmission. Then a brief introduction to the difference between the networking and data transmission technology of the data link system is made. Based on this, it proposed a data link networking and data transmission simulation system scheme, and the function of the system working process are analyzed, which provide the test and evaluation support for the construction of data link. Finally, the construction of the data link and test evaluation system and developing trend is prospected. The validation effect of the proposed methods in the data link test simulation and evaluation system is good, thus providing the reference and basis for the design of the data link system.